Antimicrobial activity of Garcinia kola against human upper respiratory tract pathogens

The antibacterial activity of aqueous and ethanolic extracts of the seeds of Garcinia kola was investigated. Agar diffusion and paper disc methods were used for the investigation. The tested organisms: Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus epidermidis, Escherichia coli and Micrococcus luteus were obtained from the Molecular Biology and Biotechnology Division of the Nigerian Institute of Medical Research (NIMR) Yaba, Lagos. Salmonella typhi was obtained from the Federal Institute of Industrial Research Oshodi (FIIRO), Lagos. Results obtained show that 75% of the tested organisms were susceptible to ethanolic extract only. 37.5% showed susceptibility to aqueous extract of the plant. It was also observed that 62.5% of the organisms tested were inhibited by mixture of ethanolic extract. Menthol showed inhibitory effect on 62.5% of the tested organisms. The diameter of the zones of inhibition of the mixture of ethanolic extract and menthol were larger than that of ethanolic extract only. The Minimum Inhibitory Concentration (MIC) ranged between 50mg/mL and 150mg/mL.E.coli showed the highest zone of inhibition (20mm). The least zone of inhibition (5mm) was observed in S. aureus and S. pnuemoniae. P. aeruginosa exhibited resistance to all the extracts. © 2011 Universal Research Publications. All rights reserved